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1、C H A P T E RINFORMATION SYSTEMS DEVELOPMENTChapter Three Information System DevelopmentDescribe the motivation for a system development process in terms of the Capability Maturity Model (CMM) for quality management. Differentiate between the system life cycle and a system development methodology. D
2、escribe 10 basic principles of system development. Define problems, opportunities, and directivesthe triggers for systems development projects. Describe the PIECES framework for categorizing problems, opportunities, and directives. Describe the essential phases of system development. For each phase,
3、 describe its purpose, inputs, and outputs. Describe cross life cycle activities that overlap multiple system development phases. Describe typical alternative “routes” through the basic phases of system development. Describe how routes may be combined or customized for different projects. Describe v
4、arious automated tools for system development.Chapter MapProcess of System DevelopmentSystem development process a set of activities, methods, best practices, deliverables, and automated tools that stakeholders (Chapter 1) use to develop and continuously improve information systems and software (Cha
5、pters 1 and 2). Many variations Using a consistent process for system development: Create efficiencies that allow management to shift resources between projects Produces consistent documentation that reduces lifetime costs to maintain the systems Promotes qualityThe CMM Process Management ModelCapab
6、ility Maturity Model (CMM) a standardized framework for assessing the maturity level of an organizations information system development and management processes and products. It consists of five levels of maturity: Level 1Initial: System development projects follow no prescribed process. Level 2Repe
7、atable: Project management processes and practices are established to track project costs, schedules, and functionality. Level 3Defined: A standard system development process (sometimes called a “methodology”) is purchased or developed. All projects use a version of this process to develop and maint
8、ain information systems and software. Level 4Managed: Measurable goals for quality and productivity are established. Level 5Optimizing: The standardized system development process is continuously monitored and improved based on measures and data analysis established in Level 4. Capability Maturity M
9、odel (CMM)Impact of System Development “Process” on QualityCMM Project Statistics for a Project Resulting in 200,000 Lines of CodeOrganizations CMM LevelProject Duration (months)Project Person- MonthsNumber of Defects ShippedMedian Cost ($ millions)Lowest Cost ($ millions)Highest Cost ($ millions)13
10、0600615.51.8100+218.5143121.3.961.7315807.728.518.933Life Cycle versus Methodology System life cycle the factoring of the lifetime of an information system into two stages, (1) systems development and (2) systems operation and maintenance. System development methodology a standardized development pr
11、ocess that defines (as in CMM Level 3) a set of activities, methods, best practices, deliverables, and automated tools that system developers and project managers are to use to develop and continuously improve information systems and software. A System Life CycleRepresentative System Development Met
12、hodologies Architected Rapid Application Development (Architected RAD) Dynamic Systems Development Methodology (DSDM) Joint Application Development (JAD) Information Engineering (IE) Rapid Application Development (RAD) Rational Unified Process (RUP) Structured Analysis and Design eXtreme Programming
13、 (XP)Principles of System Development Get the system users involved. Use a problem-solving approach. Establish phases and activities. Document through development. Establish standards. Manage the process and projects Justify systems as capital investments. Dont be afraid to cancel or revise scope. D
14、ivide and conquer. Design systems for growth and change.Use a Problem-Solving ApproachClassical Problem-solving approach1. Study and understand the problem, its context, and its impact.2. Define the requirements that must be meet by any solution.3. Identify candidate solutions that fulfill the requi
15、rements, and select the “best” solution.4. Design and/or implement the chosen solution.5. Observe and evaluate the solutions impact, and refine the solution accordingly.Establish Phases and ActivitiesOverlap of System Development PhasesManage the Process and ProjectsProcess management an ongoing act
16、ivity that documents, manages, oversees the use of, and improves an organizations chosen methodology (the “process”) for system development. Process management is concerned with phases, activities, deliverables, and quality standards should be consistently applied to all projects. Project management is the process of scoping, planning, staffing, organizing
